eng fundamentals Flashcards
energy
what is the capacity of a system to do work or produce an effect
thermodynamics
is the study of the interrelationship between the two major categories of energy
thermal energy
type of energy associated with systems of molecules. stored : internal energy. In transition: heat
mechanical energy
type of energy associated with a system composed of bodies larger than atomic particles. Stored: potential or kinetic energy. In transition: work
potential energy
type of energy with the ability of a substance or object to do work based on its location relative to the system in which it is contained
kinetic energy
the ability of a substance or object to do work based on its motion
temperature
a measure of the average random molecular kinetic energy (MARMKE). How fast particles are moving (liquid or gas) or vibrating (solid)
pressure
a ratio of force applied over an area P=F/A
WORK
the movement of an object by a force through a distance
power
the rate at which work is performed
efficiency
compares the output of a system to the work input
0th law of thermodynamics
if two bodies A and B are at the same temperature body C is at the same temperature as B, then all three bodies are at the same temperature
1st law of thermodynamics
The law of conservation of energy. energy can neither be created nor destroyed. Only altered in form.
closed system
no flow of mass into/out of system boundaries
open system
mass crosses system boundaries (into/out of system)
2nd law of thermodynamics
heat will not flow from areas of low temperature to high temperature unless some work is done on the system. Heat flows from hot to cold
newton’s third law of motion
for every action there is an equal and opposite reaction
bernoulli’s equation
as velocity increases, the pressure exerted by the fluid decreases. When fluid speed over a surface is manipulated, pressure changes
ideal gas
a theoretical gas composed of randomly moving, non-interacting particles. pressure, volume, and temperature of a gas are all directly related. PV=nRT
What is the difference between potential and kinetic energy?
Potential energy is the ability of a substance or object to do work based on its location relative to the system in which it is contained. Kinetic energy is the ability of a substance or object to do work based on its motion
Describe how Bernoulli’s equation relates to lift for a Naval aircraft
bulk mass flow rate is assumed to be constant, and the fluid on top of the wing must travel a farther distance over the same time, velocity at the top of the airfoil/propeller will go up. This in turn causes a drop in pressure above the blade and an increase in pressure below the blade. This difference in pressure will produce an upward force called lift
